Proxying Distribution Requests
If a Windows Media server connects to a Windows Media cache proxy server and requests a distribution feed from an upstream server, a proxy plug-in can instruct the cache proxy server to open a connection to the upstream server and proxy the content on demand even if the same content is currently being proxied as either a broadcast or on demand. For example, if four players and two distribution servers connect to the cache proxy server and request the same broadcast, the cache proxy server can open three connections to the upstream server, one for all of the players and one for each distribution connection.
If an authentication plug-in is enabled on the origin server, an authentication challenge is sent to the cache proxy server. The cache proxy server passes the challenge through to the distribution server, and it passes the response back to the origin.